Automobile air inlet system with hydrocarbon trap

The utility model relates to an automobile air inlet system with a hydrocarbon trap. The air inlet system for an engine comprises an air filter box used for holding an air filter box dividing the box into an atmosphere side and a filtered air side, a clean air pipeline that is connected from the downstream of the air filter box to the upstream of the air filter box relative to air flow direction in the engine operating process, a radial flow hydrocarbon trap disposed in the clean air pipeline, and a bypass hydrocarbon trap that is fixed to the filtered air side of the air filter box and provided with a plurality of generally flat or curling hydrocarbon adsorption material layers that are clamped and fixed. A mechanical fastening element such as a grommet can extend and pass through a plurality of layers to fix the layers. The fastening element is fixed to a rib part that is extended along the upper surface of the air filter box or the inner surface of the clean air pipeline.